Microwave spacers and method of use

ABSTRACT

Disclosed is a microwave spacer for guiding and positioning microwave energy delivery devices during a surgical procedure. The microwave energy device spacer includes a body forming a plurality of device apertures defined therein, the plurality of device apertures including at least two lumens and at least one arcuate slot. The lumens are configured to receive an energy delivery device therethrough. The arcuate slot includes a length, a width and a radius of curvature and is configured to receive an additional energy delivery device therethrough.

BACKGROUND

1. Technical Field

The present disclosure relates to apparatuses, systems and methods for providing energy to biological tissue and, more particularly, apparatuses, systems and methods for precise placement of microwave energy delivery devices during a surgical procedure.

2. Background of Related Art

Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high radio-frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. In monopolar electrosurgery, a source or active electrode delivers radio-frequency energy from the electrosurgical generator at a predetermined frequency to the tissue and a return electrode carries the current back to the generator. In monopolar electrosurgery, the source electrode is typically part of the surgical instrument held by the surgeon and applied to the tissue to be treated and a patient return electrode is placed remotely from the active electrode to carry the current back to the generator. In bipolar electrosurgery, the active and return electrodes are placed in close proximity to each other, e.g., at the surgical site, and electrosurgical currents are passed therebetween. In microwave electrosurgery, the antenna of the microwave energy delivery device generates electromagnetic fields in the adjacent tissue without the generation of electrosurgical currents between an active electrode and a return electrode as discussed hereinabove.

Radio-frequency energy may be delivered to targeted tissue in an ablation procedure by electrosurgical probes or by an electrosurgical antenna. In the case of tissue ablation using electrosurgical probes, electrode pairs are positioned in the surgical site to deliver high frequency electrosurgical currents between the pairs of active (+) and return (−) electrodes. An active (+) electrode and a return (−) electrode may be positioned in a spaced apart relationship on the shaft of an electrosurgical probe such that electrosurgical currents are passed along, or parallel to the shaft.

Alternatively, a first probe may function as an active (+) electrode and a second probe may function as a return (−) electrode. The first and second probes are positioned in a spaced apart relationship relative to each other such that electrosurgical currents are passed between the active (+) and return (−) electrodes resulting in the ablation of tissue positioned between the two probes. As such, the ablation region is defined by the spacing between the active (+) and return (−) electrodes and heating of tissue is typically confined therebetween. During ablation, current pathways in tissue between the active (+) and return (−) electrode produce localized heating between the two probes.

Radio-frequency energy in a microwave frequency range may be delivered to a targeted tissue by a microwave energy delivery device with a microwave antenna on the distal tip. The antenna of the microwave energy delivery device, when provided with a microwave energy signal, generates electromagnetic fields in the adjacent tissue without the generation of electrosurgical currents between an active electrode and a return electrode as discussed hereinabove.

While the ablation region produced by ablation probes is defined by the current path between the electrodes, the ablation region (shape and area) produced by a microwave energy delivery device is defined by the type of antenna, the frequency of the microwave energy signal and the power level of the microwave energy signal. For example, an ablation region generated by a microwave energy delivery device may be symmetric about the tip and shaft of the microwave energy delivery device, directed to only one side of the shaft or if the antenna is unchoked, the ablation region may include a “tail” portion that extends proximally along the elongated shaft of the microwave energy delivery device.

Unlike radio-frequency probes, microwave energy delivery devices need not be configured to interact with each other. In fact, microwave energy delivery devices typically do not interact since any interaction would be due to the intermingling of the electromagnetic fields generated by the two devices (i.e., the two devices placed in close proximity may result in the overlapping of electromagnetic fields generated by each microwave energy delivery device). The overlapping electromagnetic fields may result in unpredictable results as the electromagnetic fields may cancel each other (resulting in no heating), the electromagnetic fields may combine (resulting in the generation of pockets of extremely high current densities) or any combination thereof. As such, controlling the interaction between microwave energy delivery devices becomes even more complicated when the surgical procedures requires the insertion of a plurality of microwave energy delivery devices.

The unpredictable nature of the overlapping electromagnetic fields can be overcome by precisely placing the microwave energy delivery devices in a target tissue.

SUMMARY

The present disclosure describes apparatuses, systems and methods for precise placement of energy delivery devices in a surgical procedure. In one embodiment, the energy delivery device spacer includes a body including a plurality of device apertures and an arcuate slot defined therein. The plurality of device apertures includes two or more lumens each configured to receive an energy delivery device therethrough. The arcuate slot has a length, a width and a radius of curvature. The arcuate slot is configured to receive an additional energy delivery device therethrough.

The spacer may further include a plurality of ribs configured to form one or more air flow apertures. The ribs may connect the lumens and the arcuate slot. The body may also include a patient facing surface that includes at least one channel configured to space a portion of the patient facing surface away from patient tissue.

In a further embodiment, the radial center of the arcuate slot radius of curvature is related to the radial center of a lumen. One position along the length of the arcuate slot and two of the lumens may form a substantially straight line and the radial centers of two lumens and the radial center of the position along the length of the arcuate slot may be evenly spaced along the substantially straight line. Another position along the length of the arcuate slot and two of the lumens may form the corners of an isosceles triangle and another position along the length of the arcuate slot and two of the lumens may form the corners of an isosceles right triangle. The body may include three lumens, each configured to receive a microwave energy delivery devices therethrough, and the radial centers of the three lumens may form the corners of an equilateral triangle.

In a further embodiment the device apertures formed by the body are substantially parallel and the microwave energy delivery devices inserted through the lumens and the arcuate slot may be substantially parallel.

In another embodiment of the present disclosure, an electrosurgical ablation system includes a microwave energy source, a plurality of microwave energy delivery devices and a microwave spacer. The microwave energy delivery devices each include a microwave antenna at a distal tip configured to receive microwave energy signals from the microwave energy source and to radiate microwave energy at a predetermined frequency. The microwave spacer includes a body including a plurality of device apertures defined therein. The device apertures may include two or more lumens and an arcuate slot having a length, a width and a radius of curvature. The lumens are each configured to receive one or more microwave energy delivery device therethrough. The arcuate slot is configured to receive an additional microwave energy delivery device therethrough. The lumens and the arcuate slot are configured to guide microwave energy delivery devices.

The body may further include a plurality of ribs configured to form one or more air flow aperture. The ribs may connect the lumens and the arcuate slot.

In a further embodiment the body may include a patient facing surface with one or more channels configured to space a portion of the patient facing surface away from patient tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a microwave spacer, in accordance with the present disclosure that is configured to position three microwave energy delivery devices in a straight line configuration with a first spacing;

FIG. 2 is a perspective view of another embodiment of a microwave spacer, in accordance with the present disclosure that is configured to position three microwave energy delivery devices in a straight line configuration with a second spacing;

FIG. 3 is a perspective view of the microwave spacer of FIG. 1;

FIG. 4 is a perspective view of the microwave spacer of FIG. 2;

FIG. 5A is a bottom view of the microwave spacer of FIG. 1;

FIG. 5B is a perspective view of the patient facing surface of the microwave spacer of FIG. 1;

FIG. 6 is a perspective view of the microwave spacer of FIG. 1 in a configuration that positions the devices at the corners of an equilateral triangle;

FIG. 7 is a perspective view of the microwave spacer of FIG. 1 in a configuration that places the devices at the corners of a first isosceles triangle;

FIG. 8 is a perspective view of the microwave spacer of FIG. 1 in a configuration that places the devices at the corners of a second isosceles triangle;

FIG. 9 is a top, perspective view of the microwave spacer of FIG. 1 with a microwave energy delivery device positioned in a selected position along the length of an arcuate slot defined within the spacer;

FIG. 10 is a top, perspective view of the microwave spacer positioned on patient tissue with the distal portions of the microwave energy delivery devices inserted in target tissue;

FIG. 11A is a perspective view of a pivotable microwave spacer, in accordance with another embodiment of the present disclosure that is configured to position three microwave energy delivery devices at the corners of an equilateral triangle;

FIG. 11B is a perspective view of the pivotable microwave spacer of FIG. 11A configured to position three microwave energy delivery devices in a straight line configuration;

FIG. 12A-12C are top views of the pivotable microwave spacer of FIG. 11A in various angular positions;

FIG. 13 is a top, perspective view of the patient facing surface of the pivotable microwave spacer of FIG. 11A; and

FIG. 14 is a top, perspective view of the pivotable microwave spacer of FIG. 11A positioned on patient tissue with the distal portion of the microwave energy delivery devices inserted in target tissue.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.

FIGS. 1 and 2 show perspective views of microwave spacers 100, 200 in accordance with one embodiment the present disclosure. Microwave spacers 100, 200 are generally constructed for use with a particular microwave energy delivery device 10. For example, the microwave energy delivery devices 10 illustrated in FIGS. 1 and 2 are penetrating microwave energy delivery devices sold by Covidien under the trademark Evident™ Microwave Ablation percutaneous antennas. Microwave spacers 100, 200 of the present disclosure may be adapted for use with any suitable tissue penetrating microwave energy delivery devices that include an antenna on the distal end and require controlled spacing therebetween. Microwave spacers 100, 200 of the present disclosure may be adapted for use with any suitable device that requires controlled spacing therebetween such as, for example, devices configure to deliver radio-frequency energy, ultrasonic energy, cryogenic energy, thermal energy, laser energy or any combination of devices or energy sources thereof.

Each body 110, 210 of the respective microwave spacers 100, 200 forms a plurality of apertures that include a central tubular lumen 102 a, 202 a, a first side tubular lumen 104 a, 204 a, a second side tubular lumen 106 a, 206 a and an arcuate slot 112 a, 212 a defined therein that extend through each body 110, 210, respectively (see FIGS. 3 and 4). In this particular configuration the microwave spacers 100, 200 include three sets of fixed position apertures (i.e., the central tubular lumen 102 a, 202 a the first side tubular lumen 104 a, 204 a and the second side tubular lumen 106 a, 206 b) and one selectable aperture (i.e., arcuate slots 112 a, 212 a).

In particular, microwave spacers 100, 200 are configured to arrange, align, position and/or configure the microwave energy delivery devices 10 for use in a surgical procedure. For example, microwave spacers 100, 200 are configured to arrange microwave energy delivery devices 10 in a substantially straight line or linear configuration (a linear configuration as shown in FIGS. 1 and 2, an equilateral triangular configuration as shown in FIGS. 5B and 6 or an isosceles triangle configuration forming an angle from between about 90° and 180°).

Each body 110, 120 of respective microwave spacers 100, 200 may form a plurality of device apertures therein and the apertures may include any combination of apertures types (i.e., fixed position apertures and/or selectable position apertures). For example, the first side tubular lumen 104 a, 204 a and the second side tubular lumen 106 a, 206 a may be replaced with a selectable position aperture, similar to the arcuate slot 112 a, 212 a, positioned radially outward from the central tubular lumen 102 a, 202 a. Another embodiment may include at least one arcuate slot and a plurality of fixed apertures or at least one fixed aperture and a plurality of arcuate slots.

Microwave spacers 100, 200 may include a plurality of sizes and/or spacing arrangements. For example, FIG. 1 illustrates a 1.5 cm microwave spacer 100 and FIG. 2 illustrates a 2.0 cm microwave spacer 200. The size of the microwave spacer 100, and/or the number and spacing of the fixed lumens 102 a, 104 a, 106 a and/or the arcuate slot 112 a may be related to the type of ablation device, a parameter related to the energy delivered by the ablation device (i.e., power, current, voltage and/or frequency of the energy), the type of surgical procedure performed and/or the length of the surgical procedure.

Patient facing surfaces 110 a, 210 a of respective microwave spacers 100, 200 face the patient and may be configured to facilitate contact with patient tissue. In one embodiment, a portion of the patient facing surface (e.g., surface 110 a) includes a surface configured to aid in securing the microwave spacer 100 to patient tissue (i.e., a non-slip pattern formed in the body). In another embodiment, a portion of the patient facing surface 110 a may include a coating or non-slip material configured to adhere to the patient, such as, for example, an adhesive coating, a non-skid cover or any other suitable surface or coating that aids in securing the microwave spacer 100 to the patient. In yet another embodiment, the microwave spacer (e.g., spacer 100) may include a plurality of appendages (i.e., feet and/or legs—not explicitly shown) or channels to elevate and/or space a portion of the patient facing surface 110 a of the microwave spacer 100 with respect to patient tissue 160 (See FIG. 10).

For the purposes herein, microwave spacer 100 is described in further detail, however, it is contemplated that any of the features described herein may be applied to microwave spacer 200. The features of the microwave spacer 200 illustrated in FIG. 4 are labeled with like-numbers of corresponding features illustrated in FIG. 3.

Body 110 includes a plurality of apertures/fixed lumens 102 a, 104 a, 106 a, 112 a to guide at least a portion of the microwave energy delivery devices 10. The fixed apertures, which include the central tubular lumen 102 a, the first side tubular lumen 104 a and the second side tubular lumen 106 a, position a microwave energy delivery device 10 in a fixed relationship with respect to the other fixed lumens 102 a, 104 a, 106 a and microwave energy delivery devices 10 inserted therethrough. The adjustable apertures e.g., arcuate slot 112 a, positions one or more microwave energy delivery devices 10 in an adjustable relationship with respect to the fixed lumens 102 a, 104 a, 106 a.

The arcuate slot 112 a is configured to receive a microwave energy delivery device 10 through a plurality of positions along its length “L”. The arcuate slot 112 a is formed along a portion of an arc formed with a radial center positioned at the radial center of the central tubular lumen 102 a and a radius of curvature (e.g., see FIG. 5A distance “D1”). The length “L” of the arcuate slot 112 a is the circumferential length between the radial centers of microwave energy delivery devices inserted through the first end 112 b and the second end 112 c of the arcuate slot 112 a. The width “W” is the width of the arcuate slot 112 a measured along the radius “R”. The width “W” is configured to receive a microwave energy delivery device 10 therethrough. The length of the arcuate slot 112 a is selected such that a microwave energy delivery device may be positioned at a plurality of positions along the length “L” of the arcuate slot 112 a to form a plurality of desirable configurations with respect the fixed lumens 102 a, 104 a, 106 a, as described herein and illustrated in FIGS. 1, 5B and 7-9. In one embodiment, the radius of curvature of the arcuate slot 112 a is selected such that radial center of the radius of curvature, formed by the arcuate slot 112 a, is related to one of the fixed apertures, e.g., as illustrated in FIG. 1, the radial center of the arcuate slot 112 a is the radial center of the central tubular lumen 102 a.

With particular reference to FIGS. 3 and 4, microwave spacers 100, 200 include a central stem 102, 202 defining a central tubular lumen 102 a, 202 a therethrough. Microwave spacers 100, 200 further include a first side tubular stem 104, 204 defining first side tubular lumen 104 a, 204 a therethrough, and second side tubular stems 106, 206 defining a second side tubular lumen 106 a, 206 a therethrough. First side tubular stems 104, 204 are connected to respective central stems 102, 202 by a first bridge 108 a, 208 a and second side tubular stem 106, 206 is connected to central stem 102, 202 by a second bridge 108 b, 208 b.

As illustrated in FIG. 5A, the first bridge 108 a, 208 a and second bridge 108 b, 208 b are off-set or angled from one another by an angle “α” equal to 60°. First side tubular lumen 104 a, 204 a of first side tubular stem 104, 204 and second side tubular lumen 106 a, 206 a of second side tubular stem 106, 206 are each spaced from central tubular lumen 102 a, 202 a of central stem 102, 202 by an equivalent distance “D1”. The distance “D1” may relate to the type of ablation device, a parameter related to the energy delivered by the ablation device (i.e., power, current, voltage and/or frequency of the energy), the type of surgical procedure performed and/or the length of the surgical procedure. In one embodiment, the distance “D1” is equal to about 0.591 in.

Microwave spacer 100 may be configured such that fixed lumens 102 a, 104 a and 106 a of respective tubular stems 102, 104 and 106 are parallel with respect to one another. Additionally, each fixed lumen 102 a, 104 a and 106 a of respective tubular stems 102, 104 and 106 may be sized and dimensioned to slideably receive a shaft 14 (see FIGS. 1 and 2) of a particularly-sized microwave energy delivery device 10.

FIG. 5B is a perspective view of the patient facing surface 110 a of the microwave spacer 100. Patient facing surface 110 a may include one or more legs 140 to elevate a portion of the body 110 with respect to patient tissue (not explicitly shown) thereby allowing air to freely flow between the patient and at least a portion of the patient facing surface 110 a (i.e., exterior bridge 109, first bridge 108 a, second bridge 108 b, first guide body support bridge 114 a and second guide body support bridge 114 b.) In use, thermal energy generated at the surface of the patient tissue (not explicitly shown) dissipates through the first airflow aperture 130 a and/or the second airflow aperture 130 b. As heat is generated at the tissue surface (i.e., tissue directly below the patient facing surface 110 a of the microwave spacer 100), a convection air current is generated wherein heated air, within the first airflow aperture 130 a and/or second airflow aperture 130 b, rises. This convection air current draws fluid through the space formed between the patient facing surface 110 a and patient tissue.

With continued reference to FIGS. 3-5B, microwave spacer 100 further includes an arcuate guide body 112 defining an arcuate slot 112 a therethrough. Arcuate guide body 112 is connected to central stem 102 by a first guide body support bridge 114 a and a second guide body support bridge 114 b. Second guide body support bridge 114 b is axially-aligned with first bridge 108 a. First guide body support bridge 114 a is oriented at an angle “θ1” relative to first bridge 108 a and oriented at an angle “θ2” with respect to second bridge 108 b. In one embodiment the angle “θ1” is about 90° and the angle “θ2” is about 150°.

A first end 112 b of arcuate slot 112 a of arcuate guide body 112 is axially aligned with first side tubular lumen 104 a of first side tubular stem 104. A second end 112 c of arcuate slot 112 a is oriented at an angle “θ1” relative to first side tubular lumen 104 a of first side tubular stem 104 and is oriented at an angle “θ2” with respect to second side tubular lumen 106 a of second side tubular stem 106. First end 112 b of arcuate slot 112 a of arcuate guide body 112 and second end 112 c of arcuate slot 112 a of arcuate guide body 112 are each spaced from central tubular lumen 102 a of central stem 102 by an equivalent distance “D1”.

With reference to FIG. 5A, arcuate slot 112 a of arcuate guide body 112 defines a radius of curvature having its center located along the central axis of central stem 102 and that is parallel to fixed lumens 102 a, 104 a and 106 a of respective tubular stems 102, 104 and 106. Additionally, arcuate slot 112 a of arcuate guide body 112 is sized and dimensioned to slidably receive a shaft 14 of a microwave energy delivery device 10 therethrough, as illustrated in FIGS. 1 and 2.

With reference to FIG. 6, tubular stems 102, 104 and 106, and arcuate guide body 112 have a height “H” that is sufficient to maintain substantial parallelism of the shafts 14 of the microwave energy delivery devices 10 inserted into the respective fixed lumens 102 a, 104 a, 106 a and arcuate slot 112 a thereof. The height “H” is sufficiently long to guide the microwave energy delivery devices 10 such that the distal ends of the devices are positioned in a desirable spaced apart relationship relative to each other such that the spacing of the distal tips S1, S2 and S3 are desirably spaced and the spacing between the distal tips S1, S2 and S3 is substantially equal.

In another embodiment, the shafts 14 of the microwave energy delivery devices 10 are not substantially parallel to each other. As such, the spacing between the distal tips S1, S2 and S3 may increase or decrease as the microwave energy delivery devices 10 are inserted through the microwave spacer 100.

Microwave spacer 100 may be constructed from any suitable material, such as a non-conductive plastic material (e.g., nylon or polyamide) or a ceramic.

Microwave spacer 100 is configured to provide a plurality of microwave energy delivery device 10 orientations with varying spacing between each microwave energy delivery device 10. FIGS. 1 and 2 illustrate a straight line configuration of the microwave energy delivery devices 10. Additional orientations and spacing between microwave energy delivery devices 10 are further illustrated in FIGS. 5B, and 6-9.

In FIGS. 5B and 6, the three fixed lumens 102 a, 104 a, 106 a position the radial centers of the microwave energy delivery devices 10 such that the radial centers form the corners of an equilateral triangle, wherein the sides of the triangle are equal to a distance “D1”, as illustrated in FIG. 5A and the equilateral triangle angle β is equal 60°.

In FIG. 7, central tubular lumen 102 a, first side tubular lumen 104 a and the second end 112 c of the arcuate slot 112 a position the radial centers of the shafts 14 of the microwave energy delivery devices 10 such that the radial centers form the corners of a right isosceles triangle with angles of 90°, 45° and 45°.

In FIG. 8, central tubular lumen 102 a, second side tubular lumen 106 a and the first end 112 b of the arcuate slot 112 a position the radial centers of the shafts 14 of the microwave energy delivery devices 10 such that the radial centers form the corners of an obtuse triangle with angles of 120°, 30° and 30°.

FIG. 9 illustrates that the shaft 14 of the microwave energy delivery device 10 inserted into arcuate slot 112 a may be positioned at any point along the length of the arcuate slot 112 a, thereby providing a plurality of configurations in which the microwave energy delivery devices 10 may be arranged.

With continued reference to FIG. 9, bridges 108 a, 108 b, 109, 114 a, 114 b provide structural strength to the microwave spacer 100 thereby preventing deflection and/or preventing the microwave spacer 100 from changing shape or form. In addition, first bridge 108 a, second bridge 108 b and exterior bridge 109 of the body 110 form the sides of a first airflow aperture 130 a. First guide body support bridge 114 a, second guide body support bridge 114 b and arcuate guide body 112 form the sides of a second airflow aperture 130 b. First airflow aperture 130 a and second airflow aperture 130 b are configured to allow heat (generated at the surface of the patient tissue) to dissipate through the microwave spacer 100. The body 110 may include one or more passageways, such as first airflow aperture 130 a or second airflow aperture 130 b, for air to flow between the patient facing surface 110 a and patient tissue (not explicitly shown). Thermal energy generated at the surface of the patient tissue (not explicitly shown) dissipates through the first airflow aperture 130 a and/or the second airflow aperture 130 b. Body 110 of the microwave spacer 100 may be formed from a light weight material resistant to thermal heating.

In yet another embodiment of the present disclosure the patient facing surface 110 a may include one or more channels 111 a, 111 b, 111 c formed therein. Channels 111 a, 111 b, 111 c form a fluid pathway for air to flow between the patient facing surface 110 a and patient tissue (not explicitly shown). As heat is generated at the tissue surface (i.e., tissue directly below the patient facing surface 110 a of the microwave spacer 100), a convection air current is generated wherein the heated air, within the first airflow aperture 130 a and/or second airflow aperture 130 b, rises. In turn, the convection air current draws fluid into the first airflow aperture 130 a and/or the second airflow aperture 130 b through the channel 111 a, 111 b, 111 c respectively. Each bridge 108 a, 108 b, 109, 114 a and 114 b may include one or more channels, formed along the patient facing surface 110 a, to provide a fluid pathway for a convection air current to flow.

In use, as illustrated in FIG. 10, a microwave spacer 100 is placed on patient tissue 160 adjacent a target tissue 160 a or tissue targeted for a medical procedure, (i.e., an ablation procedure, a resection procedure or any other suitable electrosurgical procedure that requires electrosurgical energy delivery). The clinician may utilize an imaging/positioning system, such as, for example, an ultrasonic system, an x-ray system, a CT scan or any other suitable imaging/positioning system (not explicitly shown) to determine proper positioning of the microwave spacer 100 with respect to the target tissue 160 a. Each of the microwave energy delivery devices 10 is inserted into a selected fixed lumen 102 a, 104 a and/or a selected position of the arcuate slot 112 a. The imaging system (not explicitly shown) may be used during the insertion step to determine when each microwave energy delivery device 10 is properly positioned in target tissue 160 a. The microwave ablation procedure may require the use of any number and/or combination of fixed lumens 102 a, 104 a, 106 a and/or arcuate slot 112 a. Apertures not used for the insertion of microwave energy delivery devices 10 may be used for the placement of a probe or sensor configured to measure a property of the target tissue such as, for example, a temperature (i.e., thermocouple, RTD or inferred heat measuring device), impedance and/or a tissue fluid content.

A method for placing a plurality of microwave energy delivery devices 10 and ablating tissue is also provided by the present invention and includes the steps of placing the microwave spacer 100 on a portion of patient tissue 160 adjacent a target tissue 160 a; inserting two or more microwave energy delivery devices 10 through fixed lumens 102 a, 104 a, 106 a formed in the body 110 of the microwave spacer 100 into the target tissue 160 a; selecting a position on the arcuate slot 112 a; inserting at least one microwave energy delivery device 10 through the arcuate slot 112 a into the target tissue 160 a; connecting the three or more microwave energy delivery devices 10 to a microwave energy source (not explicitly shown); ablating the target tissue 160 a by delivering microwave energy through the microwave energy delivery devices 10; and cooling patient tissue 160 by providing airflow through a plurality of airflow apertures formed through the body 110 of the microwave spacer 100.

Another method for placing a plurality of microwave energy delivery devices 10 and ablating tissue includes the steps of: placing the microwave spacer 100 on a portion of patient tissue 160 adjacent a target tissue 160 a; inserting two or more microwave energy delivery devices 10 through fixed apertures formed in the body 110 of the microwave spacer 100; advancing an antenna 12 of the microwave energy delivery devices 10 to the target tissue 160 a; inserting another microwave energy delivery device 10 in a selected insertion position in an arcuate slot 112 a forming in the body 110 of microwave spacer 100 and into the target tissue; connecting the microwave energy delivery devices 10 to a microwave energy source; and ablating the target tissue by delivering microwave energy through the microwave energy delivery devices 10.

The methods may further include the step of cooling the patient's tissue by providing airflow through a plurality of channels 111 a, 111 b, 111 c formed in the body 110 of the microwave spacer 100.

One or more of the afore described methods may further include the step of inserting one or more sensors 115 through a lumen (i.e., fixed lumens 102 a, 104 a, 106 a, as illustrated in FIG. 10, or a selected position on arcuate slot 112 a) formed in the body 110 of the microwave spacer 100 into the target tissue. The sensor 115 may be configured to measure a property of the target tissue such as, for example, a temperature (i.e., thermocouple, RTD or inferred heat measuring device), impedance and/or a tissue fluid content.

FIGS. 11A-14 show various views of a pivotable microwave spacer 300 in accordance with the present disclosure. Pivotable microwave spacer 300 is generally constructed for use with a particular microwave energy delivery device 10. For example, the microwave energy delivery devices 10 illustrated in FIGS. 11A, 11B, 13 and 14 are sold by Covidien under the trademark Evident TM Microwave Ablation percutaneous antennas. Pivotable microwave spacer 300 of the present disclosure may be adapted for use with any suitable device that requires controlled spacing therebetween such as, for example, devices configure configured to deliver radio-frequency energy, ultrasonic energy, cryogenic energy, thermal energy, laser energy or any combination of devices or energy sources thereof.

The body 310 of the pivotable microwave spacer 300 includes a first body 311 and a second body 312 pivotally attached thereto. First body 311 includes an upper first body member 311 a, a lower first body member 311 b and a first body spacer 311 c. Second body 312 includes a second body member 312 a and a second body stop 312 b. Upper first body member 311 a and lower first body member 311 b each form a portion of the pivot aperture 304 therein. Second body member 312 a forms a second body pivot aperture 304 b therein disposed in vertical registration with respect to first body pivot aperture 304 a formed in the first body 311. First body pivot aperture 304 a and second body pivot aperture 304 b pivotally attach the first body 311 and second body 312 about the pivot aperture 304.

As illustrated in FIG. 11A, the first body 311 forms a first body aperture 302 and the second body 312 forms a second body aperture 306. In this particular embodiment the first body aperture 302, the pivot aperture 304 and the second body aperture 306 are equally spaced from each other thereby forming the corners of an equilateral triangle. In another embodiment, first body 311 and/or second body 312 of the pivotable microwave spacer 300 may form two or more apertures therein. For example, in one embodiment the first body 311 and/or the second body 312 form at least two apertures therein and form a pivotable microwave spacer 300 for positioning microwave energy delivery devices 10 along a resection line wherein the resection line includes at least one variable angle.

As illustrated in FIG. 11A, the angular relationship between the first body 311 and second body 312 is adjustable between a minimum angular relationship and a maximum angular relationship. The size and/or position of the second body stop 312 b determine the maximum and minimum angular relationship between the first body 311 and the second body 312. For example, in FIG. 11A the second body stop 312 b limits the angular relationship between the first body 311 and the second body 312 between about 60° and about 300°, wherein the second body stop 312 b makes contact with the upper first body member 311 a at the minimum and maximum angular relationships between the first body 311 and second body 312. In another embodiment, the second body stop 312 b limits the angular relationship between the first body 311 and the second body 312 between about 30° to about 330°. In yet another embodiment, the second body stop 312 b limits the angular relationship between the first body 311 and second body 312 between about 60° and 270° wherein at 60° the centers of the apertures 302, 304, 306 form the corners of an equilateral triangle and at 270° form the corners of an isosceles right triangle wherein a right angle is formed at the pivot aperture 304 (composed of first body pivot aperture 304 a and second body pivot aperture 304 b.

In another position, as illustrated in FIG. 11B, the first body 311 and second body 312 are positioned at 180° with respect to each other, wherein the first body aperture 302, second body aperture 306 and pivot aperture 304 form a substantially straight line therebetween. FIGS. 11A and 11B illustrate only two positions of a plurality of angular positions wherein the angle between the first body 311 and the second body 320 varies between about 60° and about 300°.

The angular relationship between the first body 311 and the second body 312 of the pivotable microwave spacer 300 may be determined by providing an angular gauge 360 as illustrated in FIGS. 12A-12C and described hereinbelow. The pivotable microwave spacer 300 illustrated in FIGS. 12A-12C is configured to provide adjustability between 60° and 300°. An angular gauge 360, as described herein, may be adapted to provide the angular relationship of any such pivoting microwave spacer.

Angular gauge 360 includes a first angular indicator 325 and a second angular indicator 326. First angular indicator 325 provides angular measurements between 60° and 180° and second angular indicator 326 provides measurements between 180° and 300°. FIG. 12A illustrates the angular relationship between the first body 311 and second body 312, as indicated by the first angular indicator 325, equal to 60° (pivoted fully counter-clockwise with the first body 311 in contact with the second body stop 312 b). FIG. 12B illustrates the angular relationship between the first body 311 and the second body 312, as measured by the first angular indicator 325 and/or the second angular indicator 326, equal to 180° (longitudinal side edges of First body 311 and second body 312 in alignment). FIG. 12C illustrates the angular relationship between the first body 311 and the second body 312, measured by the second angular indicator 326, equal to 270°. Angular gauge 360 indicates the angular position between the first body 311 and the second body 312 through the entire range of rotation between the first body 311 and the second body 312.

In a further embodiment, as illustrated in FIGS. 13A and 13B, pivotable microwave spacer 300 may further include a locking and/or holding mechanism (e.g., ratchet 395 and catch 390 or notch 391 and recessed channels 396) to lock and/or hold the first body 311 in a desirable position with respect to the second body 312. Ratchet 395 includes a plurality of ratchet teeth 395 a configured to engage catch 390. Catch 390 is biased against ratchet 395 and engages one or more ratchet teeth 395 a or any portion of the ratchet 395 thereby preventing further rotation of the first body 311 with respect to the second body 312. Catch release 390 a, positioned in catch release aperture 311 d formed in the first body 311, when pressed disengages the catch 390 from the ratchet 395.

As illustrated in FIG. 13B, the first body 311 and second body 312 include mechanically interfacing surfaces configured to engage and/or lock the first body 311 in a desirable position with respect to the second body 312. For example, upper first body member 311 a of the first body 311 may form a notch 391 that engages at least one of a plurality of recessed channels 396 a-396 ad formed in the second body member 312 a of the second body 312. When assembled, notch 391 aligns with the plurality of recessed channels 396 and incrementally engages the recessed channels (e.g., engages recessed channel 396 a and subsequently engages channel 396 b, etc. . . . ) as the position of the first body 311 is adjusted with respect to the second body 312. In a further embodiment, recessed channels 396 a-396 ad may be incrementally spaced, such as, for example, spaced in 10° intervals as illustrated in FIG. 13B.

In a further embodiment, as illustrated in FIG. 13, pivotable microwave spacer 300 may include a plurality of legs 340 a-340 f configured to facilitate contact with the patient. Legs 340 a-340 f are configured to elevate at least a portion of the pivotable microwave spacer 300 such that the pivotable microwave spacer 300 is substantially parallel to patient tissue. In one embodiment, feet 340 e, 340 f are only included on the second body 312 wherein each foot e.g., foot e.g., foot 340 e, 340 f, elevates the second body 312 the thickness “T” of the lower first body member 311 b. Legs 340 a-340 f may include a coating or non-slip material that adheres to the patient, such as, for example, an adhesive coating, a non-skid cover or any other suitable surface or coating that aids in securing the pivotable microwave spacer 300 to the patient.

In another embodiment, the pivotable microwave spacers 300 may include an arcuate slot or non-arcuate slot as described hereinabove.

In use, as illustrated in FIG. 14, pivotable microwave spacer 300 is placed on patient tissue 160 adjacent a target tissue 160 a e.g., tissue targeted for a medical procedure, (i.e., an ablation procedure, a resection procedure or any other suitable electrosurgical procedure that requires electrosurgical energy delivery). The clinician may utilize an imaging/positioning system, such as, for example, an ultrasonic system, an x-ray system, a CT scan or any other suitable imaging/positioning system (not explicitly shown) to determine proper positioning of the pivotable microwave spacer 300 with respect to the target tissue 160 a. Each of the microwave energy delivery devices 10 is inserted into a respective aperture 302, 304, 306 and into patient tissue 160. An imaging system (not explicitly shown) may be used during the insertion step to determine when each microwave energy delivery device 10 is properly positioned in target tissue 160 a. Apertures not used for the insertion of microwave energy delivery devices 10 may be used for the placement of a sensor 115 configured to measure a property of the target tissue such as, for example, a temperature (i.e., thermocouple, RTD or inferred heat measuring device), impedance and/or a tissue fluid content.

In yet another embodiment, a microwave spacer (not shown) in the spirit of the present disclosure is formed by including three or more bodies that form an interlocking microwave spacer, wherein each of the three or more bodies includes at least one aperture formed therein. The three or more bodies may be daisy-chained together or may be grouped together in a specific pattern. The connection between the three or more bodies may be accomplished by connection points formed on the bodies or by utilizing a linking connector configured to link together two or more microwave spacers.

A method for placing a plurality of microwave energy delivery devices 10 and ablating tissue includes the steps of: selecting an ablation pattern; providing a pivotable microwave spacer 300; adjusting the angular relationship between the first body 311 and second body 312 of the pivotable microwave spacer 300; placing the pivotable microwave spacer 300 on a portion of patient tissue 160 adjacent a target tissue 160 a; inserting two or more microwave energy delivery devices 10 through apertures formed in the first body 311 and/or the second body 312 of the pivotable microwave spacer 300 and into the target tissue 160 a; connecting the microwave energy delivery devices 10 to a microwave energy source (not explicitly shown), and ablating the target tissue 160 a by delivering microwave energy through the microwave energy delivery devices 10.

The method may further include the step of cooling patient tissue 160 by providing airflow between the pivotable microwave spacer 300 and patient tissue 160.

The methods may further include the step of inserting one or more sensors 315 through an available aperture (e.g., apertures 302, 304, 306 formed in the pivotable microwave spacer 300) and into the target tissue 160 a. The sensor 315 may measure one or more properties of the target tissue 160 a such as, for example, temperature (i.e., thermocouple, RTD or inferred heat measuring device), impedance and/or a tissue fluid content.

While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. 

What is claimed is:
 1. A spacer configured to position energy delivery devices including: a body including a plurality of device apertures defined therein, the plurality of device apertures comprising: at least two lumens each configured to receive an energy delivery device therethrough; and at least one arcuate slot having a length, a width and a radius of curvature, the at least one arcuate slot configured to receive an additional energy delivery device therethrough at a plurality of positions along the length thereof.
 2. The spacer according to claim 1, wherein the body further includes a plurality of ribs configured to form at least one air flow aperture.
 3. The spacer according to claim 2, wherein the plurality of ribs connect the at least two lumens and the at least one arcuate slot.
 4. The spacer according to claim 1, wherein the body further includes a patient facing surface, the patient facing surface including at least one channel configured to space at least a portion of the patient facing surface away from patient tissue.
 5. The spacer according to claim 1, wherein the body further includes a patient facing surface, the patient facing surface including a plurality of legs that elevates at least a portion of the patient facing surface away from patient tissue.
 6. The spacer according to claim 1, wherein a radial center of the radius of curvature of the at least one arcuate slot is related to a radial center of one of the at least two lumens.
 7. The spacer according to claim 6, wherein at least one of the plurality of positions along the length of the at least one arcuate slot and two of the at least two lumens form a substantially straight line.
 8. The spacer according to claim 7, wherein a radial center of two of the at least two lumens and the radial center of the at least one of the plurality of positions along the length of the at least one arcuate slot are about evenly spaced along the substantially straight line.
 9. The spacer according to claim 6, wherein at least one of the plurality of positions along the length of the at least one arcuate slot and two of at least two lumens form an isosceles triangle.
 10. The spacer according to claim 9, wherein at least one of the plurality of positions along the length of the at least one arcuate slot and two of the at least two lumens form the corners of an isosceles right triangle.
 11. The spacer according to claim 1, wherein the at least two lumens includes at least three lumens, the at least three lumens each configured to receive an energy delivery device therethrough and a radial center of each of the at least three lumens form an equilateral triangle.
 12. The spacer according to claim 1, wherein the plurality of device apertures are substantially parallel.
 13. The spacer according to claim 12, wherein energy delivery devices inserted through the at least two lumens and the at least one arcuate slot are configured in a substantially parallel manner.
 14. An electrosurgical ablation system, comprising: a microwave energy source; a plurality of microwave energy delivery devices each including a microwave antenna at a distal tip thereof, the microwave antennas configured to receive microwave energy signals from the microwave energy source and to radiate microwave energy at a predetermined frequency therefrom; a spacer configured to position the plurality of microwave energy delivery devices including: a body including a plurality of device apertures defined therein, the plurality of device apertures comprising: at least two lumens each configured to receive a respective one of the microwave energy delivery devices therethrough; and at least one arcuate slot having a length, a width and a radius of curvature, the at least one arcuate slot configured to receive an additional microwave energy delivery device therethrough at a plurality of positions along the length thereof.
 15. The system according to claim 14, wherein each of the at least two lumens and the at least one arcuate slot are configured to guide one of the plurality of microwave energy delivery devices.
 16. The system according to claim 14, wherein at least one of the plurality of positions along the length of the at least one arcuate slot and two of the at least two lumens form a substantially straight line.
 17. The system according to claim 16, wherein a radial center of two of the at least two lumens and a radial center of at least one of the plurality of positions along the length of the at least one arcuate slot are about evenly spaced along the substantially straight line.
 18. The system according to claim 14, wherein at least one of the plurality of positions along the length of the at least one arcuate slot and two of the at least two lumens form the corners of an equilateral triangle.
 19. The system according to claim 14, wherein at least one of the plurality of positions along the length of the at least one arcuate slot and two of the at least two lumens form an isosceles triangle.
 20. The system according to claim 14, wherein the body further includes: a plurality of ribs forming at least one air flow aperture, the plurality of ribs connecting a first portion of the body including the at least two lumens and a second portion of the body including the at least one arcuate slot; and a patient facing surface, the patient facing surface including at least one channel configured to space at least a portion of the patient facing surface away from patient tissue. 